» » Achondroplasia - Causes, Symptoms, Diagnosis, Treatment


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What is Achondroplasia?

Achondroplasia is a rare genetic disorder of bone growth that causes short-limbed dwarfism. The short stature is caused because of a problem of conversion of cartilage of the skeleton into bones during early development. This process called ossification is specifically affected in the long bones of the arms and the legs.

The trunk is of average size while the head is often large. This combination results in an abnormally short stature. All persons with achondroplasia are little people.


What are the Causes of Achondroplasia?

Mutations in a single gene called the FGFR3 gene located on chromosome 4 cause achondroplasia.

In 80% of children, the condition is caused due to a spontaneous new mutation in a gene from average-sized parents. The condition may also be inherited from one generation to the next. The inherited gene is considered dominant, since even one mutant copy of it (even when one parent has an altered gene) can cause achondroplasia. The presence of two copies of the gene is considered lethal causing stillbirths or early death.

The FGFR3 gene encodes for a protein called the fibroblast growth factor receptor 3 (FGFR3). The receptor is attached to the surface of cells called fibroblasts that make collagen and other structural materials needed for the tissues and the bones. The receptor regulates bone growth by controlling the process of ossification.

The mutation in the fibroblast gene causes a mutated or a faulty receptor which in turn results in severely shortened bones.

Facts and Statistics on Achondroplasia

  • Achondroplasia is one of the oldest known birth defects. An average figure worldwide is approximately 1 in 25,000 births.
  • The average height of an adult with achondroplasia is 131 cm (52 inches, or 4 feet 4 inches) in males and 124 cm (49 inches, or 4 feet 1 inch) in females.
  • Intelligence is entirely normal in patients with achondroplasia.

What are the Symptoms and Signs of Achondroplasia?

Clinical features of achondroplasia include the following:
  • Large head with prominent forehead and less developed midface
  • Short arms and legs when compared to the trunk length. This is particularly noticeable in the upper arms and thighs. This results in disproportionate short stature
  • A protruding jaw sometimes with poor dental structure. The teeth are crowded and the upper and lower teeth may be poorly aligned
  • Fingers appear short and the ring and middle fingers diverge giving the hand a trident (three-pronged) appearance
  • "Double" jointedness, caused by lax (loose) ligaments in some joints. Many achondroplastic children can flex their finger, wrist, hip, and knee joints to an extreme degree because of this ligamentous laxity
  • Prominence of the mid-to-lower back with a small hump. The hump present at birth goes away with walking and a pronounced sway of the lower back becomes apparent
  • Symptoms of Achondroplasia
  • Bowed legs
  • Decrease in muscle tone (hypotonia)
  • Delayed motor milestones in children with achondroplasia
  • Narrowing of the spinal canal that can pinch the spinal cord resulting in difficulty in walking due to associated pain, tingling and weakness in the legs
  • Fluid accumulation in the brain called hydrocephalus
  • Recurrent ear infections
  • Obesity
  • Temporary stops in breathing called apnea


How Do You Diagnose Achondroplasia?

Achondroplasia is diagnosed with the help of the following tests:
  • Preconception - If there is an affected parent or family member, genetic counseling for the parents is advised to explain the chances of the baby suffering from the  condition
  • Prenatal - If short limbs are detected on routine ultrasound, a high resolution ultrasound is recommended. When there is a family history, a DNA test can also be done to diagnose achondroplasia. The DNA can be obtained by a procedure called chorionic villus sampling (CVS) or amniocentesis.
Prenatal Diagnosis Helps Detect Achondroplasia

If achondroplasia has been confirmed before the birth of the baby, genetic counseling for the parents is advised to explain the possible consequences of the condition and a neonatologist has to be consulted.

Postnatal - When short limbs are seen in a newborn, radiologic studies have to be done for skeletal survey and a clinical geneticist has to be consulted. Radiologic details often show a large skull, the bones of the extremities being short with irregular growth plates, and broad hands with short bones and a trident configuration.


How Do You Treat Achondroplasia?

At present, there is no specific treatment to promote growth in children with achondroplasia. Surgery may be used for lengthening of limb bones up to 12-14 inches and correction of bowed legs. Growth hormones can have a modest growth in some children. When special problems complicate achondroplasia, prompt and expert intervention is important.
  • The spinal cord compression can require surgery to decompress it
  • To relieve pressure on the brain, fluid from the head has to be drained
  • Obstructive apnea can be corrected by removing adenoids and tonsils or by surgically opening the airway (tracheostomy) in severe cases
  • Frequent middle-ear infections and any hearing loss due to it have to be monitored
  • Hunched back will have to be surgically corrected if it is not automatically corrected before the child starts walking
  • Inward curving of the lower back can be corrected by special exercises or physical therapy
  • Exercises May Help Straighten the Inward Curving Of The Lower Back
  • Teeth should be straightened and, if necessary, removed to alleviate dental problems
  • Obesity should be monitored by standard weight and weight by height grids and not by body mass indexes
Little people have the same intelligence as others. They are no different from the rest. What they need is careful monitoring and support for social adjustment in a world structured for people with normal height.

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Hello i m from pune i like to know in India Achondroplasia consider as Handicapped or not plz help me Reply plz
onkar89 Saturday, April 27, 2013
when is rondals and whos tuesday??? why is timmy frolicking in my rabbit garden? tom plus tree equals arab. aaron went to the market to buy chicken but he got carrots thinking it was tom.
oh121212 Monday, March 18, 2013
Achondroplasia is serious it makes your head big and your limbs short its not fun sometimes my head gets too heavy and i fall over and i cant reach the light switch in the bathroom so i poop in the dark
dwarfmaster11 Wednesday, May 8, 2013
can people suffering from achondroplasia conceive?? and can a girl of 20yrs old can b treated for achondroplasia??? please reply
clits94 Saturday, February 16, 2013
KIA28SINGLE Wednesday, February 8, 2012
gd day, im peter frm nigeria, my baby is diagonised of achondroplasia by a doc in lagos teaching hospital, idi araba. she is a yr old. pls what can i do at least to increase her height.
pet35 Monday, February 6, 2012

My is 17 in normal stream of education. He seemed fine but has a painful calf whenever he walks. He has hydrocephalus too. He is now wanting to get help in learning to drive. However I have no means to support that. Any advise will be helpful.
He is bow leg but presumably if you ask your doctor for advise about correcting they will direct you to the appropriate surgeon. The other is stretching leg while she is resting. My son is not too concern whereby I did not seek any help in the area.

LeonKwang94 Saturday, January 14, 2012
can anyone please get to know me about fee structure regarding bow leg correction treatment... pleae...
anikamways Friday, October 21, 2011
I stay in Gurgaon, India. My daughter was diagnosed of achondroplasia just 10 days before her birth. She is 3.5 years old now and goes to school-playgroup and thoroughly enjoys it. We plan to continue her normal education. Though there are no immediate concerns except the height factor, we realize that we should be providing her with some tools and equipments, that make her independent and facilitate her in leading a normal life. For example – a] something that continuously strengthens her knee, b) somethings that helps her manage her basic hygiene requirements, c) somethings that helps her in the bathroom/kitchen, d) somethings that help her with the electric switches, e) somethings that help her climbing stairs and f) any other tool/equipment which would have come in handy to anyone in the group. I would really appreciate if anyone can share their experiences with these. I am happy to share my specific experiences, if required. Regards, Pankaj
pankajmadan Tuesday, February 1, 2011
Hi Pankaj, I am from Greater Noida and my was son daignosed with achondroplasia in 8th month. He is 5 now and goes to school. Would like to share expirence and any other information which would be helpful for our kids.
Vaman Friday, July 22, 2011
Hi Vaman, I think we should surely get in touch and share some experience/information. My mail id is Regards, Pankaj
pankajmadan Tuesday, July 26, 2011
hello. i also had the same situation like your, that i got to know abt my son s disorder in last son is 1.5 years old now..but still he can not able to sit by himself...he is using brace to support his back, but still he can not sit...please do tell me your daughter s growth chart...thank u ..
Ayesha82 Tuesday, August 16, 2011
A very fine article on achondrplasia. Nevertheless,I would have preferred a greater supplementation with clinical photographs and radiographs for driving home the important aspects of this common proble.
If desired, I can share some of the clinical pictures with your readers please.
Dr (Prof) Suraj Gupte, MD, FIAP

surajgupte Tuesday, June 29, 2010

I'm Virginia and i have a 11 month old baby who has been diagnosed with Achondroplasia. My husband is also a dwarf, but I love my family. It is complicated to have baby with Achondroplasia, however I have overcome my fears and have cared for him over a year now. My baby is very handsome, and we have got involved in a club and LPA. Kindly comment if you too would like to join.

vicky09 Monday, May 24, 2010

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